Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* eBPF mini library */
2#include <stdlib.h>
3#include <stdio.h>
4#include <linux/unistd.h>
5#include <unistd.h>
6#include <string.h>
7#include <linux/netlink.h>
8#include <linux/bpf.h>
9#include <errno.h>
10#include <net/ethernet.h>
11#include <net/if.h>
12#include <linux/if_packet.h>
13#include <arpa/inet.h>
14#include "libbpf.h"
15
16static __u64 ptr_to_u64(void *ptr)
17{
18 return (__u64) (unsigned long) ptr;
19}
20
21int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
22 int max_entries)
23{
24 union bpf_attr attr = {
25 .map_type = map_type,
26 .key_size = key_size,
27 .value_size = value_size,
28 .max_entries = max_entries
29 };
30
31 return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
32}
33
34int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
35{
36 union bpf_attr attr = {
37 .map_fd = fd,
38 .key = ptr_to_u64(key),
39 .value = ptr_to_u64(value),
40 .flags = flags,
41 };
42
43 return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
44}
45
46int bpf_lookup_elem(int fd, void *key, void *value)
47{
48 union bpf_attr attr = {
49 .map_fd = fd,
50 .key = ptr_to_u64(key),
51 .value = ptr_to_u64(value),
52 };
53
54 return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
55}
56
57int bpf_delete_elem(int fd, void *key)
58{
59 union bpf_attr attr = {
60 .map_fd = fd,
61 .key = ptr_to_u64(key),
62 };
63
64 return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
65}
66
67int bpf_get_next_key(int fd, void *key, void *next_key)
68{
69 union bpf_attr attr = {
70 .map_fd = fd,
71 .key = ptr_to_u64(key),
72 .next_key = ptr_to_u64(next_key),
73 };
74
75 return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
76}
77
78#define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))
79
80char bpf_log_buf[LOG_BUF_SIZE];
81
82int bpf_prog_load(enum bpf_prog_type prog_type,
83 const struct bpf_insn *insns, int prog_len,
84 const char *license)
85{
86 union bpf_attr attr = {
87 .prog_type = prog_type,
88 .insns = ptr_to_u64((void *) insns),
89 .insn_cnt = prog_len / sizeof(struct bpf_insn),
90 .license = ptr_to_u64((void *) license),
91 .log_buf = ptr_to_u64(bpf_log_buf),
92 .log_size = LOG_BUF_SIZE,
93 .log_level = 1,
94 };
95
96 bpf_log_buf[0] = 0;
97
98 return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
99}
100
101int open_raw_sock(const char *name)
102{
103 struct sockaddr_ll sll;
104 int sock;
105
106 sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
107 if (sock < 0) {
108 printf("cannot create raw socket\n");
109 return -1;
110 }
111
112 memset(&sll, 0, sizeof(sll));
113 sll.sll_family = AF_PACKET;
114 sll.sll_ifindex = if_nametoindex(name);
115 sll.sll_protocol = htons(ETH_P_ALL);
116 if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
117 printf("bind to %s: %s\n", name, strerror(errno));
118 close(sock);
119 return -1;
120 }
121
122 return sock;
123}